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Fencer Vulns
medium 6.1

CVE-2021-20133 json

Quagga Services on D-Link DIR-2640 less than or equal to version 1.11B02 are affected by an absolute path traversal vulnerability that allo…

published 2021-12-30 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7590

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

Quagga Services on D-Link DIR-2640 less than or equal to version 1.11B02 are affected by an absolute path traversal vulnerability that allows a remote, authenticated attacker to set the "message of the day" banner to any file on the system, allowing them to read all or some of the contents of those files. Such sensitive information as hashed credentials, hardcoded plaintext passwords for other services, configuration files, and private keys can be disclosed in this fashion. Improper handling of filenames that identify virtual resources, such as "/dev/urandom" allows an attacker to effect a denial of service attack against the command line interfaces of the Quagga services (zebra and ripd).

Exploit prediction

2.14% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • tenable.com https://www.tenable.com/security/research/tra-2021-44 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H
NVD 2.0 7.1 AV:A/AC:L/Au:S/C:C/I:N/A:C

Affected products

  • n/a Quagga Services on D-Link DIR-2640 Routers

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.